Chemical feeder and method of feeding



Oct. 21, 1952 FARRELL 2,614,574

CHEMICAL FEEDER AND METHOD OF FEEDING Filed April 12, 1948 2 SHEETSSHEET 2 FIG.3.

I5 I H I 3 /6 I6 20 /a 20 l6 '8' 3 DE -L INVENTOR.

JAMES KENNETH FARRELL /\9| ATTORNEY.

Patented Oct. 21, 1 952 CHEMICAL FEEDER AND FEEDING- J'ames' Kenneth Farrell, Syracuse, N." Y1, assiirno1" j to Allied Chemical &'- Dye Corporation; New York, N. Y.', a corporationofNew York METl IODQF Application April 12', 1948;.Serial'No.20378 1. l

This invention relates't'o' dispensing water soluble solidsand more particularly refersto a newand improved method and" apparatus for feeding controlled amounts of caustic detergentsto'maintain' the caustic concentration'in a bath at a desired concentration.

The control of caustic solutions" for washing bottles, peelingof'fruits and vegetables, and the swelling of WOOd' bolts for pulpingha's presented a difficult problem for many years. Most states have enacted rigid laws'to controlthe washing of bottles used" by the public'forsuchproduc'ts as milk, soft drinks and beer; Up to the present time there has been no satisfactory method of controlling the caustic concentration in soaker tanks of bottle washers. The problem is adifiiculton'e' for a number of reasons. The concen'- tration used in these tanks is relatively high} running-from 2% to '5% dependingon'the particular State law. Such high concentrations are' difiicult'to maintain by'any type of feeder 'which operates mechanically or on a constant flow basis. Neither of these types of-leeder has proved successful because they arenotuniform in their delivery characteristics and because of variable demand for make up alkali. A further objection is that excess waterin theform' of caustic solution results in the loss of valuable caustic by overfiow'sin'ce the water make up required in even a large bottle washing machine rarelyamounts to morethan 150"gallo'n's per'24 hours. Because of these and other difiiculties, it is" the practiceto attempt to main'tainth'e re; quired concentration by means of frequent manual buck-up of the solution with'solid'caustic alkalies. I

- Manual control of thecaustic concentration is obviously undesirable. The safetyhazard-in volved in handling large I amounts of solid or flake caustic alkali I at frequent" intervals is'one' that allbottlers would 5 prefer to avoid?- The practice is wasteful in that I frequently 'the so'aker' tankis permitted to drop to a concentration" below that which producesoptimum" cleaning. and "then the whole" volume" is brought up. to a concentration well above that necessary; In fact in many cases the concentration is made so high that actualattackof-the bottles by the caustic results. These:wide sw-ings' in concentration are" the inevitable-result of the attempts ofthe operating rpersonnelto save time:

c'ent'ratioir in bottlelwashingfl machines. If the lye concentration ishigIier than required; it ima pairs the. quality "of the 'itrejated fruits and vegetables, whereas if "the lye concentration drops'to too low a point-the fruit and vegetables. arein adequately" treated; requiring either further seame -tor wast ,t H

The addition of solid causticalkalito soluti I for" maintainin ithe proper concentration .ther inby'mea'ns of 'anautomfatic feederjp'resents number "of serious problems; particularlvthat .ofj' designing and operating a dispenser which will,

' measure out regulated amounts of caustic to? tolerated. Furthermore. theaddition of dilute solution's'of caustic results in the loss of caustic maintain the required concentration inthejsol tion inaccordancewith the depletion of caustic from the solution; The'hyg roscopic nature of caustic compounds in general and the highly humid conditions surrounding the bottle iv'ashg.

ing machine orthefp'eeli ngf apparatus combine to complicatef thisfp'roblerii. o m gknqwledse. no automatic chemical feeder Of SOi1 l'dS" has been commercially'embloyed for this pur'nose."

The-addition of c u stic' solutions for make purp rrses to alkali solutions employed'inf'bottle washing mach lnes an dfrui t and vegetable peeling apparatus isfrequently objectionable, 1 In the case of'bottle washing or' peeling of fruits solutions havinga hig'h-degreebf caustic' alkalinity aremaintained 'withoutrenlacementever:

a long periodsof-ftime; Many caustic type deter' 2 gentcompoundscannot bemadeup to more than c 10% concentration because atroom temperatures higher concentrations will ryaa1 aeor congeali Thus; the volul el'bf" water addedper unit" of. caustic resultsinmore Zdilution than-can-be by overflow. The introduction of caustic soluti'ons involves" certain practical difliculti'es' to be. overcome suc'h asfkeepin'ga" control valve in operation'with solutions which areliable to' crys' tallize' at'the slightest droo in temnerature. Otherobjectionsto theuse ofsuch caustic solua tionsa're" (l) the" necessityflfor largetanks' for Which ther'e may 'be no available space, and (2) the preparation of 'suchsolutions is messy and dangerous. r T One object of the present invention is. to ,nro vid'e' an 1 effi'cient method of feeding caustic detergents' in regul'ated amounts to solutions requiring maintenance" of concentration, within na'rr'ow limitswithout substantially diluting the solutions. a 1 I, k

Another object-of this H mention is" to provide a slinple economical dispenser for feedin'g'highly tions which pass directly intotheaqueousbath.

to replenish the loss in solute. thereim the; aqueous bath may be maintainedat. a predeter mined concentration within narrow limits with none of the serious difliculties attendant previous methods for maintaining a substantially constant concentration in' a bath.

While I do not wish.to predicate my invention on. any theory;. the followin explanation. will indicate the reasons for. the. manifold advantages of the present invention over the prior; art.

(11) The quantity. of'caustic. detergent. fed into. an aqueous bath in the present invention is,de termined by the amount of. steam. introduced into. the dispenser. containing; solid. caustic detergent and the passage. of. concentrated caustic solutions, from the. dispenser into. the. aqueous,

bath is accomplished. through a large. unobstructed path, whereas in. the. usual. procedure.

the: flowof. caustic. solutions; is. regulated at. the. outlet. of. the. dispenser. by meansof. valves. or

other. impedances. with. consequent. frequent. plugging. up of the. passageway, leading to the, aqueous bath due to.so1idifying.or congealing of the.concentratedcausticsolution.

(b) In. any device for. regulatingthediow. of. fluids; particularly one... which is. responsive. to. a solution. frequently varying in. concentration,.

there is always ,a time .lag; resultingjn .overshootingthe mark. Byemployingsteamasa medium. for formingconcentrated caustic ..solutions.-much closer response of caustic. feed to variations concentration. of an aqueous bath canbe obtained. This will. be. apparent when it will.be..

considered thattheratio. byvolumeof one pound. saturated. steam. to one. pound-water. at=-212 F.

and atmospheric pressure; is. roughly. 1600 to. 1. (c). Caustic solutions, of. higher concentration" can. be. madeby. contactingsteam. with. solid: caustic compounds. rather. than, water since. thetotal heat content of. steam is- 1150. B.t.u;. per pound, divided ,into. 180 B.t.u. ,for. sensible; heat. and. 970 I B.t.u. for latent heat of vaporization, as. compared to, the total. heat content. of 180'.-

B.-t.u. for: waten at. 2122 511. allot-which issensible.

heat. When either. steam. or water enters thev dispenser there-is aloss of. heat: dueto radia-'- tion, convection. or. conduction; When: hot water. is introduced. in.contact with. solid caustic compounds in.a .container, the. resulting. solution will dropinttemperature. since the sensible heat of the Water and the. heat. of solution gene erated will quickly be dissipated resulting in solidification of concentrated. caustic solutions therein unless large amounts of'water. are. added. which produce caustic solutions of low concen tration. With. steam there is. available. 970 Btu.- perpound. to compensate, forv heatlosses. before there is any drop in temperature.

((1) Steam rapidlyforms concentrated caustic. solutions when contacted with. caustic. solid invention.

4 due to the high heat content of steam and its large volume per unit weight and vapor condition which permit greater dispersion and better contact with the caustic solid. The time required for water to dissolve caustic solid to produce a concentrated caustic solution comparable with. that made by steam; is appreciably greater.

(e). Since; highly concentrated. caustic solutions are produced by contacting steam with caustic solid, stoppage of the flow of steam into the dispenser will cause a lowering of temperature therein with almost immediate solidification of the concentrated solution and discontinuance. of discharge into the aqueous bath. Whenwater. is:employed to dissolve caustic solid, the flow of causticsolution into the aqueous bath cannot be quickly terminated Without a valve mechanism or other restriction and the dimculties' attendant thereto.

In the accompanying; drawings I have illustrated oneembodiment of. the inventionby way of example, thoughait will be clear. that the.

novel methodymay be carried out in other. ways, and-thatthe apparatus may be modified with-- out departing fromthe scope and. spirit of the This invention. may be applicable for the maintenance. of the. concentration. of aqueous solutions for purposes other. than those cited.

herein. Illustrative examples of Waterrsoluble.

" solids suitableior. use in the. practice ofmy in.-

vention. are caustic. soda, soda ash, detergent. compounds, potash and .caustic potash.

Fig.1. is a diagrammatic. flow sheet. of one.

method of practicingmy invention.

Fig. 2 is anexplodedpartialsection. of a. front elevation of. the.v dispenser showin a preferred.

form. of cover. disengaged. from the. dispenser.

Fig.3 is a sectionalview taken on. line 3.3. of Fig. 2 with apart of. the screen cut away.

Referring to, Fig.1, tank. I containing aqueous.

' sistance between thecontact points. of the-electrodes. The, solution resistance between the electrode contacts forms onearm of a Wheatstone bridge inthe control circuit. During the operation of the bottle washer or. peeling machine the caustic concentration in solution 2 steam jets l8.

decreases either. through consumption. or dilu-- tion resulting in. anincreased resistance between thecontact points of electrodesi. The-increasein. resistance is transmitted by electrode leads 4 to controller 5. As the bridge becomes un.- balanced due to:v the: increase in resistanceresulting from the-decrease in: caustic concentration, the unbalance-causesa relay in controller.- 5 to becperated. electronically which, in turn through solenoid leads 6 operates solenoid. valve 1 interposed in steam.line..-8. Steam from any suitable external source is supplied through eons duitv 9, strained to remove foreign matter in steam strainer" H; passed through steam trap l2 to separate the steam from the condensed water and thence flows through solenoid valve 1 through line 8 into dispenser I 3.

The operation of solenoid 1 permits steam to enterthe'steam distributing ring l6 shown" in Figs. 2 and.3 from which itissues through- The steam then contacts the solid caustic. compound: in; container [3. Theheat of wet steam and theheat of-solution of the; caustic causes.=thez formation of ahighly a rmen-i concentrated" solution' of th'e caustiG- cOD P W usually- 60 -70 wliich-passes through the 'scre'en andout thfough' the conical bottom section H irito' caustic 'solution 2 contained in- -sol'ution tank I The addition -o'f the" concentrated caus' tic solution to caustic solution 2 causes a --'grad-ual decrease inthe resistance across contacts J of i electrodes 3; This decrease in resistance finally:

reachesa pointwhere balance of the Wheat-' stone bri'dge in the control-circuit 'is again restored and the relay in" controller '5 actuating solenoidwalveifl is-"released thereby stopping Since theconw 'centration "of' the caustic solution-issuing "from" dispenser I3 is 'very -high; as soon as the steam ceases to flow the"'ca'usticsolution solidifies a1- ni'ost' immediatelythereby reducing e overshooting of the concentrationof aqueous solution. 2 in tank I aimi'nimum.

.Although -not 'aipreferred method ofoperation; the introduction of steam inte -dispenser I 3 ma'y be regulated-byrmanual i manipulation of a ralve mime-'8; I I

.Eig; 2:-'is a-tfront view ofidispenserfl3-fiwithf conicalexbase' F I 4 showing zine section steam dis tributing ring I6 andsteam -jetsIB placed Jim mediatly above' screen I'I-.supportingsolid caustic' compoiindi 20. Concentrated caustic solution: passing -througli screen .I -'I flows .downwardlyxibyx gravity.:througliunobstructed -con'ical section I4 I out" through enlarged opening. I 9 1 into caustic solution immediately below? Cover :2 I for "en closingdispens'er I3 .is.:preferably provided with ash'allow cone-ishapedxbott'om 22-"which permits the-condensed I moisture on -its surface :tozdrip down over the?caustic'fromithe 'center' ofzthe' cover. I

Fig; s illustrates'iin greater detail thenconstruction of caustic dispenser I3 'which 7? com- D'rises -'a cylindrical metal -shell I 5 and a steam distributing.- ring: I6 disposed adjacent themin tern'alperiphe'ry" of shell- I5 andimmediately:

above screen 1 I 1. Steam enters "ringil Ii throu'gh conduit 8-and issues from the ringIthrough -four jets IE' Which' -direct theIsteam' -in contact with solid" caustic compound: 2|}:vv supported by:: the screen-x, The concentrated causticrsolution result ingx-from the mixture of steamand SO1i'd-f Ca,l1S"-" tic. "discharges through lthe large ropeningi I 9 I at' theabottom" of'conical section? I45 i To further illustrate th "advantages" of my? invention; :a": series-of tests wereconductd Jon apparatus inthe manner previously; described in: connection with Fig; 1 of; th'eaccompanying drawing.- Solution 2 contained'in tank I was con stantly being depleted of caustic soda andithe'nireplenished' with highly "concentrated caustic I soda solution from dispenser I3. lt was'vfound that three:-"caustic soda'" solutions" of different concena trations could 'be maintainedswitl'lint-the :fo11ow=- inge ,limits :1 3:47 %'i0.12 ,I 5'.65*'%i0;18'%-;-1-and 11:38 %i0.89% These tests demonstrate that in wherebyfa rconcentratediiaque'ous solution orrsaid solid iis iproduced :and flows :through said: ipera.

forated member;- and iiuponi termination of. steam V introduction solidifies on said perforated zmemw ber terminating I flow: o'f-qaqueous solution therethrough, said disp'enser being' adapted :to 'dis-.-

sipa'te heat -to cause dr'opin temperaturexand solidification: of aqueous. solution on perforated memberpwithdr'awing said concentrated solution, bygravity through: an outlet in said container,

and maintaining a continuous open passageway from the perforated member throughthe :outlet.

of the container r during dischargingand ,nondischarging" periods of "dispensing concentrated solution; 7 v 2." A method'fordispensing-a controlled amount. of hygroscopic caustic solid which comprises ine troducing'i st'eam.;in contact with a hygroscopic caustic solid maintained.- in. a container and sup- K ported upon a :perforated member, regulating the amount of steam introduced in accordance with the amount of-sai'd solid .desired to berdis pens'ed, whereby 'a'iconcentrated aqueous solution produced; and flows through said and" upon termination of steam-introduction*solidifies on said perforated member: terminating fiow of aqueous'solution therethrough,: said dispenser being adapted to of said solid is perforated member,

dissipate heat toscause drop in temperature and solidification of aqueous solution on perforated member, withdrawing, said concentrated the-"practice of' myinventi'orr I cant maintain-z 'solution' by. gravity through an outletinsaid container; andmaintaining a continuous .open

passageway from the perforated member through the 'outletaof the container during discharging and non-discharging periods of dispensing concentrated solution,

3. A method for dispensing a controlled amount of caustic soda which comprises introducing; steam in contact with solid caustic'soda -main tained in a container and supported upon a perforated member, regulating the amount of steam introduced inaccordance with the amount of said solid desired to be dispensedywherebya -concen-, trated aqueous solution of said solid is produced andflows'through said perforated member, and upon termination'of steam introduction solidifies on said perforated member terminating flow of aqueous: solution: therethrough, saiddispenser beingadaptedto dissipate heat to cause drop in temperature and solidification'of aqueous solution on perforated member, withdrawing *said, concentrated solution by gravity through an out-- let in said container, and maintaining-a continu ous'open passageway from the perforated ;mem her-through theuoutlet of thecontainer during discharging and non-discharging} periods ,of dis-n pensing concentrated solution.

4.:A" dispenser for discharging a controlled amount: of hygroscopic, solid which comprises -.-'a

container having 'a tapered bottom section open at its lower end, aperforated member: in said container adapted: to: support a hygroscopic solid of high; solubilit athigher temperatures in water,

': a'=continu'ousopen passageway fromthe :perfoe I rated member through the outlet of the container; a-.steam distributingyring;disposed a short dis- I tance above said" perforatedxmember, a plurality,

of 1 jets extending from 'said ring;v to. introduce g steam? into. said: 'containeri'f or contact" with saidf hygroscopic: solid; whereby a concentrated Iaqueous solution 'of'isaid solidis produced land flows, through:said-perforated member, and; upon termination "of steam 'introductiontsolidifieskon'rsaid:

perforated member terminating flow; o'fr aque-i ouss solution'ltherethroughf :said: dispenser.--bei-ng:.-

adapted to dissipate heat to-causedrop-in tern-.-

peratureiandisolidificationof aqueous solution on the perforated member, a steam inlet conduitw having one. end conneotedto saidiring and its other end "being: adapted. to be connected ,1 to. .a 1

suitablersupply of steam from an external source,

avaIVe-mechanism interposed in said steam inletw conduitiadapted to regulate the amount of steam in'said'container until a predetermined amount of hygroscopic solid in solutionpis dispensed, and a.

cover for the top 'of said container.

5.1A dispenser for at higher temperatures in water whichzcomprisesea' container having az'cylindricalsection open'rat I its :top endand aconical bottom section.

open at its:.lower end, a 12?].6 mesh screenrinterposed between the cylindrical and conical sections to support said hygroscopic solid; 7 a' continuous open passageway from the screen throughthe outletof the container; a. steam distributingring, disposed immediately :above said screen; said ring: having a plurality'of'spaced jets pointingxin. a

direction' over 'saidiscreem whereby upon intro:

duction of steam aconcentratedaqueous-solution l of said solid is produced .andxfiows. through" said screen and upon termination of steam introduc tion solidifies on saidscreen'terminating fiow of aqueous solution therethrough; said dispenser being adapted to dissipate: heat: to; cause dropr-in temperature and solidification of aqueous solutiontonthe screen, a steam inlet-conduitxextende ing'out from said ring'adapted to be'connected': to-asuitable supply of steam from aneXternal source, a valvemechanisminterposed in saidsteam inlet conduit adapted to: regulate the;

solution of said solid is produced and flows through said perforated member, and upon termination of steam introduction solidifies on said perforated member terminating flow of aqueous solution'therethrough, said dispenser beingadapted' to dissipate heat to cause drop in' temperature and solidification of aqueous solution on the perforated member, passing said concentrated solution by gravity through an outlet in said container into a depletedaqueous bath, maintaining a continuous-open passagaway from said perforated member through the outlet of the container during discharging and non-discharging periods of "dispensing concentrated solution, and regulatingintroduction of amount ofsteam in said container in accordance with variations in concentrationof said aqueous bath thereby maintai'ning'saidaqueous bath within narrow'limits of a predetermined concentration.

7. A method for controlling the concentration ofan aqueous bath containing'caustic soda which comprises introducing steam in contact with solid cautsicsoda-maintainedin a container. and supported upon a perforatedimember, whereby a concentrated aqueous solution of said solid is produced-and fiowsithrough .said perforated meme discharging controlledv amounts: of hygroscopic solid of high solubility.

b8 111 andtuponstermination of; steam ntroduction solidifies v"on saidyperforated member terminating flow :of, aqueous solution; therethrough,-; said ;dis,- penser being adapted to dissipateiheat' to causes.

- drop inztemperature and solidification-of aqueous:

solutionon the perforated member, passing:'said concentrated solution by gravity through anoutw let in said container into a depleted aqueous bath; maintaining a continuous open-passageway-fromw said perforated member-through the outlet; ofw the container duringdischarging and nonedis, charging-periods of dispensingconcentrated 50111-1 tion, and automatically V-regulating introduction r of amount of-steam in saidcontainer'inaccorde. ance, with variationsrin;concentration 'ofisaidraqueous :bath thereby maintaining said aqueous; bathawithin marrow" limits. of a predetermined? concentration; I 1 8. Dispensing apparatus for controlling theconcentration of fan Y aqueous bath containing a hygroscopic solid as-a solute including: in com-' bination an aqueous bath, apair of electrodesirr:

said aqueous bath, a control circuit with a relayai' operatively responsive to changes in resistance between contacts" of said electrodes resulting: from changesain concentration of said aqueous bath,: a solenoid valveactuated :by said: relayiforregulating :aflow of steam, a I container having a'tapered bottom section open at its :lower end; ascreen in said container. adapted. to support a hygroscopic .SOlid'Of' high solubility at higher I temperatures. in waten a" steam distributing ring immediately above said screen; said ring having' auplurality of spaced jets pointing in a directionover said screen; a steamconduit for conducting; steam from said solenoid valve into said ring? whereby a concentrated aqueous solution of said solid is produced and flows through said screen, and. upon-.terminationof steam introduction solidifies on saidj screen: terminating. 'fiowrof; aqueous solution therethrough, said dispenser beingadapted todissipate heat to cause drop in temperature and'solidification ofaqueous solo-"- tion-onthe screen, and said container being dis-z posed above the-- level of said aqueous bath" whereby concentrated solutions of hygroscopic solid produced by the introduction of steam into said container-pass: by gravity through'zalcon tinuous openpassageway from the-screen through the bottom opening of said container directly. into saidaqueous'bath. 9. Dispensing apparatus for controlling'theconcentration of angaqueous bath containinga hygroscopic solidas, a solute including-incombination a container open at'its lower-end, a

perforated member in b said container adapted to support a hygrosgopic solid. of; high: solubility; at higher temperatures in water, a continuous" open-passageway from the perforated member through the outletof the containerthrough which concentrated solution flows by gravity,a steamconduit for introducing steam-above said perfor ated-member in contactvwith said hygroscopic solidificationof aqueous solutionon the perfo c rated member; an aqueous bath disposed ber-v neath said perforated member to; receive said concentrated. solution, a valvemechanism in said steamconduitfor regulating flow of steam into said container and control means actuatin said valve mechanism effecting flow of steam into said container responsive to changes in concentration of said aqueous bath to maintain said concentration within narrow limits.

10. A method for maintaining the concentration of a solution in use and for dissolving a hygroscopic solid of high solubility at higher temperatures in water which comprisess'ubjecting a bed of the solid maintained in a dispenser and supported upon a perforated member to the action of steam added in accordance with the response of a sensing device to the concentration of the aqueous solution whose concentration is to be maintained, whereby a concentrated aqueous solution of said solid is produced and fiows through said perforated member, and upon termination of steam introduction solidifies on said perforated member terminating flow of aqueous solution therethrough, said dispenser being adapted to dissipate heat to cause drop in temperature and solidification of aqueous solution on the perforated member, and allowing the water solution of the solid to flow out of the dispenser through a continuous open passageway from the perforated member through an outlet of the dispenser by gravitational fiow into 10 for introducing steam above said perforated member in contact with said hygroscopic solid. whereby a concentrated aqueous solution on said solid is produced and flows through said perforated member, and upon termination of steam introduction solidifies on said perforated member terminating fiow of aqueous solution therethrough, said dispenser being adapted to dissipate heat and cause drop in temperature and solidification of aqueous solution on the perforated member, an aqueous solution whose concentration is to be maintained disposed beneath said container, a continuous open passageway from the perforated member through the outlet of the container to permit the concentrated solution of solid to flow out of the container by gravitational fiow into the aqueous solution and a sensing device adapted to regulate the introduction of steam to the container in accordance with the concentration of the aqueous solution whose concentration is to be maintained.

' JAMES KENNETH FARRELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name 1 Date 1,353,035 Fairley Sept. 14, 1920 1,500,096 Oxley July 1, 1924 1,861,058 -Jaenecke May 31, 1932 2,058,300 Cramer Oct. 20, 1936 2,377,363 Noble .June 5, 1945 

1. A METHOD FOR DISPENSING A CONTROLLED AMOUNT OF HYGROSCOPIC SOLID WHICH COMPRISES INTRODUCING STEAM IN CONTACT WITH A HYGROSCOPIC SOLID OF HIGH SOLUBILITY AT HIGHER TEMPERATURES IN WATER MAINTAINED IN A CONTAINER AND SUPPORTED UPON A PERFORATED MEMBER, REGULATING THE AMOUNT OF STEAM INTRODUCED IN ACCORDANCE WITH THE AMOUNT OF SAID SOLID DESIRED TO BE DISPENSED, WHEREBY A CONCENTRATED AQUEOUS SOLUTION OF SAID SOLID IS PRODUCED AND FLOWS THROUGH SAID PERFORATED MEMBER, AND UPON TERMINATION OF STEAM INTRODUCTION SOLIDIFIES ON SAID PERFORATED MEMBER TERMINATING FLOW OF AQUEOUS SOLUTION THERETHROUGH, SAID DISPENSE BEING ADAPTED TO DISSIPATE HEAT TO CAUSE DROP IN TEMPERATURE AND SOLIDIFICATION OF AQUEOUS SOLUTION ON PERFORATED MEMBER WITHDRAWING SAID CONCENTRATED SOLUTION BY GRAVITY THORUGH AN OUTLET IN SAID CONTAINER, AND MAINTAINING A CONTINUOUS OPEN PASSAGEWAY FROM THE PERFORATED MEMBER THROUGH THE OUTLET OF THE CONTAINER DURING DISCHARGING AND NONDISCHARGING PERIODS OF DISPENSING CONCENTRATED SOLUTION. 